Original paper

Equation of state and compressibility of phlogopite by in-situ high-pressure X-ray powder diffraction

Pavese, Alessandro; Levy, Davide; Curetti, Nadia; Diella, Valeria; Fumagalli, Patrizia; Sani, Alessandra

Abstract

The elastic properties of a natural phlogopite have been studied by in-situ high-pressure X-ray powder diffraction experiments on the ID9 beamline at the ESRF, at room temperature. Several EoS models (Birch-Murnaghan, Vinet, Poirier-Tarantola) have been fitted to the experimental P-V data and the results obtained are presented and discussed. The third-order Birch-Murnaghan EoS, assuming V 0 fixed at its experimental value, yields K 0=49.7(0.5) GPa, K0'=8.59( 0.19), K0''=-0.5953 GPa-1 (implied value). The axial compressibilities at room conditions, determined by the third-order Birch-Murnaghan EoS, result in EoSa0=3.48(5), EoSb 0=3.2(1), EoSc 0=13.2(1) 10-3GPa-1. Equilibrium thermodynamic calculations have been carried out to show how the new elastic parameters here reported affect the stability field of phlogopite.

Keywords

phlogopitehigh pressureequation of statecompressibility.